The mysterious coffee shop appears identical to a normal Starbucks cafe — just with the word "Dumb" slapped in front of everything. KABC reports intrigued customers lined up around the block for their very own dumb cup of dumb coffee. (Via Twitter / @dumbstarbucks)

The store even has its own selection of typical Starbucks music by the register. This Instagram user noted these CDs were not for sale, which is a shame because we could really go for some dumb Norah Jones.

Dumb Starbucks made a splash on social media after celebrities Dan Harmon and Rainn Wilson posted pictures of the store on Twitter and Instagram.

That led Gawker to conclude: "The fact that Dan Harmon of Community, and Rainn Wilson were among some of the first to post about it on social media suggests a dumb TV show angle."

As part of an opening weekend promotion, all drinks served at Dumb Starbucks were free of charge — which, as KCAL reports, was probably for the best.

"That's really horrible ... I have no clue what this is, but I supposedly ordered this."

So, maybe the coffee's not the best, but is it even legal? Forbes has obtained a copy of the store's in-house FAQ, which claims the store is free to mimic Starbucks — because it's a parody.

"By adding the word 'dumb' we are technically 'making fun' of Starbucks, which allows us to use their trademarks under a law known as 'fair use.' ... Although we are a fully functioning coffee shop, for legal reasons Dumb Starbucks needs to be categorized as a work of parody art."

Now, the store's claim as a fully functioning coffee shop is somewhat questionable. A KPCC reporter notes "On Sunday, there still was no business license or health code rating posted in the establishment. The baristas said they were hired from Craigslist."

And as for their fair use claim to Starbucks's logo? Well, we're not lawyers, but the Harvard Law School's definition of trademark law says Dumb Starbucks might be on some shaky ground.

While parodying a trademark is somewhat protected under the First Amendment, the school notes ​"the courts appear to be more sympathetic to the extent that parodies are less commercial, and less sympathetic to the extent that parodies involve commercial use of the mark."

So if Dumb Starbucks actually starts selling coffee, they might be in trouble.

The Dumb Starbucks owners might also want to examine the fate of The South Butt, a clothing line parodying The North Face. In 2009 The North Face sued The South Butt, claiming their parody confused consumers and diluted The North Face's trademark. (Via Carter Law Firm)

That case was settled out of court. A Starbucks representative confirmed Sunday that Dumb Starbucks is not affiliated with Starbucks. The company is apparently looking into the matter.